Radium effects on aquatic organisms (radiation)

加拿大是积极参与完整核燃料循环的少数几个国家之一，包括铀矿开采和碾磨、燃料精炼和制造、核电和医疗同位素生成以及相关废物管理。目前，加拿大所有正在作业的铀矿都位于萨斯喀彻温省，该省还可以开发另外两个铀矿/铀矿厂。加拿大对核燃料循环的积极参与和严格的管理监督为该国带来了重大的经济利益。与这种燃料循环有关的铀的开采、研磨和精炼会产生残留物。加拿大法规要求对这些残留物进行安全管理，包括工艺废水、尾矿和废石库存。在受关注的放射性核素中，镭（Ra-226）特别重要，因为它的半衰期长（~1600年），与其直接子（氡）相关的危害，在一些常见环境条件下的高迁移率以及在组织中生物积累的潜力。虽然加拿大对采矿废水中的镭有管制限制，但没有关于保护水生生物的Ra-226准则。该项目的总体目标是为加拿大核工业和环境监管机构提供13种主要水生生物的基本镭毒性数据。具体研究目标是：1)确定敏感端点，量化Ra-226对水生生物的低水平影响；2)在与环境相关的镭活性浓度下，利用水生生物生成一套连贯的Ra-226慢性毒性数据；3)开发具有实验室间交叉验证的可靠分析程序，以量化环境基质（水和组织）中Ra-226的低活性；4)量化选定生物体中的Ra-226生物积累，以供我们的项目合作伙伴采用剂量建模方法。毒性测试结果将允许生成必要的物种敏感性分布（SSD），以得出保护加拿大水生生物的水质准则。长期目标是建立一个放射毒性研究网络，开发方法和技术，培养未来的科学家。

Canada is one of the few countries actively involved in the full nuclear fuel cycle, including uranium mining and milling, fuel refining and fabrication, nuclear power and medical isotope generation and associated waste management. Currently, all operating uranium mines in Canada are located in Saskatchewan and two more mines/mills in this province could be developed. This intense Canadian involvement in the nuclear fuel cycle and stringent regulatory oversight has significant economic benefits to the country. The mining, milling and refining of uranium associated with this fuel cycle produces residues. Canadian regulations require safe management of these residues, including process wastewaters, tailings and waste rock stockpiles. Among the radionuclides of concern, radium (Ra-226) is of particular importance due to its long half-life (~1600 years), the hazards associated with its immediate daughter (radon), its high mobility under a number of common environmental conditions and its potential for bioaccumulation in tissues. While there are Canadian regulatory limits for radium in mining effluents, there is no Ra-226 guideline for the protection of aquatic life.The overall objective of this project is to provide the Canadian Nuclear industry and environmental regulators essential radium toxicity data for 13 key aquatic organisms. The specific research objectives are: 1) to identify sensitive endpoints to quantify low-level effects of Ra-226 on aquatic organisms; 2) to generate a coherent set of Ra-226 chronic toxicity data using aquatic organisms at environmentally relevant activity concentrations of radium; 3) to develop robust analytical procedures with inter-laboratory cross validations to quantify low activities of Ra-226 in environmental matrices (water and tissues); 4) to quantify Ra-226 bioaccumulation in selected organisms to feed dose modelling approaches by our project partners. The toxicity test results will allow the generation of a Species Sensitivity Distribution (SSD) necessary to derive a water quality guideline for the protection of aquatic life in Canada. The long-term goal is to establish a radiotoxicity research network to develop methods and technologies and train future scientists.